48 PRIMARY OR PALÆOZOIC ROCKS.—CASE X. 
geological survey, at the Mia-mia, on the Heathcote Road, no bottom 
being found at a depth of 30 feet. The conglomerate ‘consists of a 
bluish-grey, very hard mud cement, sometimes having a slight yellow 
tinge (specimen 46), and in places interstratified with veins of an alumi- 
nous mineral. It becomes much lighter in color by exposure and soon 
crumbles to pieces. The pebbles contained in it vary much in size and 
consist of granites of various colors and textures, principally red and 
white; porphyries, indurated sandstones, quartz, red, white and blue. 
flinty quartzites; and a peculiar flint-colored rock, with red felspar 
crystals, weathering white. From one of the constituents of this latter 
rock having externally decomposed in horizontal lines, it has the appear- 
ance, at first sight, of gneiss. ‘This deposit forms a very good, red soil, 
but is boggy and rotten in winter. At this locality it is very thin, the 
Silurian rocks cropping up in the almost flat gullies. On the Wild: 
Duck Creek, however, a fine section—in many places at least 90 feet 
above the level of the creek—may be seen under Robertson’s Station 
(specimens 48, 49 and 50). The conglomerate is here capped by a 
yellowish grit (specimen 50), and rests on yellow sandstone (specimen 
49), forming large open downs. About two miles higher up the Wild 
Duck Creek, near Wilton’s Station, the beds may be seen filling up 
depressions in the upturned edges of the Lower Silurian. 
51, COPPER SLATE. j 52. LIMESTONE. 
Mansfield, Devil ’s River. Burnt Creek, near Mansfield. 
i $ Dark and crystalline. 
This specimen contains 2 per cent. of Iron and alumina ... 2°92 
copper. In the mass the amount of Carbonate of lime ... 95°55 
copper varies. Carbonate of copper and Magnesia ... +». trace 
lime occur in spots between the lamin. Silica and insoluble } 1°53 
matter ... gE 5 

100°00 


This limestone makes excellent lime. It does not, however, occur 
in large quantity, and appears to consist of a few large and small blocks 
and boulders, partly embedded in the alluvium of two small, dry gullies, 
the sides of which consist of Upper Silurian shales and sandstones. 
Whether these blocks are the last remnants of a limestone formation that 
once covered the Silurian rocks of this locality, or are transported masses, 
«is uncertain. ‘The nearest known limestone, of similar character, occurs 
in Gippsland, near the copper mine on the Thomson. ‘There are other 
large patches on the Buchan River and also at Bindi, near Livingstone. 
53. DENSE Quartz ROOK. ' 54, BROWN SANDSTONE. 
List No. R (i) Chinery’s Station, Devil’s River. 
Near Lock-up, Roses Gap. With fossil plants. 


